// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_
#define UI_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_

#include <vector>

#include "ui/events/event_constants.h"
#include "ui/views/views_export.h"

namespace gfx {
class Canvas;
class Path;
class Point;
class Size;
}

namespace ui {
class GestureEvent;
class KeyEvent;
class Layer;
class MouseEvent;
class PaintContext;
class ScrollEvent;
class TouchEvent;
}

namespace views {
class Widget;

namespace internal {

    ////////////////////////////////////////////////////////////////////////////////
    // NativeWidgetDelegate
    //
    //  An interface implemented by the object that handles events sent by a
    //  NativeWidget implementation.
    //
    class VIEWS_EXPORT NativeWidgetDelegate {
    public:
        virtual ~NativeWidgetDelegate() { }

        // Returns true if the window is modal.
        virtual bool IsModal() const = 0;

        // Returns true if the window is a dialog box.
        virtual bool IsDialogBox() const = 0;

        // Returns true if the window can be activated.
        virtual bool CanActivate() const = 0;

        virtual bool IsInactiveRenderingDisabled() const = 0;
        virtual void EnableInactiveRendering() = 0;

        // Called when the activation state of a window has changed.
        virtual void OnNativeWidgetActivationChanged(bool active) = 0;

        // Called when native focus moves from one native view to another.
        virtual void OnNativeFocus() = 0;
        virtual void OnNativeBlur() = 0;

        // Called when the window is about to be shown/hidden.
        virtual void OnNativeWidgetVisibilityChanging(bool visible) = 0;

        // Called when the window is shown/hidden.
        virtual void OnNativeWidgetVisibilityChanged(bool visible) = 0;

        // Called when the native widget is created.
        // The |desktop_widget| bool is true for widgets created in the desktop and
        // false for widgets created in the shell.
        virtual void OnNativeWidgetCreated(bool desktop_widget) = 0;

        // Called just before the native widget is destroyed. This is the delegate's
        // last chance to do anything with the native widget handle.
        virtual void OnNativeWidgetDestroying() = 0;

        // Called just after the native widget is destroyed.
        virtual void OnNativeWidgetDestroyed() = 0;

        // Returns the smallest size the window can be resized to by the user.
        virtual gfx::Size GetMinimumSize() const = 0;

        // Returns the largest size the window can be resized to by the user.
        virtual gfx::Size GetMaximumSize() const = 0;

        // Called when the NativeWidget changed position.
        virtual void OnNativeWidgetMove() = 0;

        // Called when the NativeWidget changed size to |new_size|.
        // This may happen at the same time as OnNativeWidgetWindowShowStateChanged,
        // e.g. maximize.
        virtual void OnNativeWidgetSizeChanged(const gfx::Size& new_size) = 0;

        // Called when the NativeWidget changes its window state.
        // This may happen at the same time as OnNativeWidgetSizeChanged, e.g.
        // maximize.
        virtual void OnNativeWidgetWindowShowStateChanged() = 0;

        // Called when the user begins/ends to change the bounds of the window.
        virtual void OnNativeWidgetBeginUserBoundsChange() = 0;
        virtual void OnNativeWidgetEndUserBoundsChange() = 0;

        // Returns true if the delegate has a FocusManager.
        virtual bool HasFocusManager() const = 0;

        // Paints the rootview in the context. This will also refresh the compositor
        // tree if necessary.
        virtual void OnNativeWidgetPaint(const ui::PaintContext& context) = 0;

        // Returns the non-client component (see ui/base/hit_test.h) containing
        // |point|, in client coordinates.
        virtual int GetNonClientComponent(const gfx::Point& point) = 0;

        // Mouse and key event handlers.
        virtual void OnKeyEvent(ui::KeyEvent* event) = 0;
        virtual void OnMouseEvent(ui::MouseEvent* event) = 0;
        virtual void OnMouseCaptureLost() = 0;

        virtual void OnScrollEvent(ui::ScrollEvent* event) = 0;
        virtual void OnGestureEvent(ui::GestureEvent* event) = 0;

        // Runs the specified native command. Returns true if the command is handled.
        virtual bool ExecuteCommand(int command_id) = 0;

        // Returns the child Layers of the Widgets layer that were created by Views.
        virtual const std::vector<ui::Layer*>& GetRootLayers() = 0;

        // Returns true if window has a hit-test mask.
        virtual bool HasHitTestMask() const = 0;

        // Provides the hit-test mask if HasHitTestMask above returns true.
        virtual void GetHitTestMask(gfx::Path* mask) const = 0;

        //
        virtual Widget* AsWidget() = 0;
        virtual const Widget* AsWidget() const = 0;

        // Sets-up the focus manager with the view that should have focus when the
        // window is shown the first time.  It takes the intended |show_state| of the
        // window in order to decide whether the window should be focused now or
        // later.  Returns true if the initial focus has been set or the window should
        // not set the initial focus, or false if the caller should set the initial
        // focus (if any).
        virtual bool SetInitialFocus(ui::WindowShowState show_state) = 0;
    };

} // namespace internal
} // namespace views

#endif // UI_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_
